5. 6) 2x*(-5x+3y)=-10x^2+6xy 7)(-2)*(3a-4b+5c)=-6a+8b-10c 8)x^3(x^2+x-2)=x^6+x^4-3^3 9)(-5y^6)*(3y^2+4y-1)=-10y^7-20y^7+5y^6 10)4a^3(2a^2-5a-3)=-8a^6-20a^2-12a^3 6. 6) (7 z -3 )(5 z -2 )=-35z^2-14z-15z+6 7)(2 — 4x)(1 — 3x)=-2-6x-4x-12x^2 8)( 3 — 2 x)(5x + 1)=-10x-3-10x^2-2x 9)(4b — 5c)(3b + 4c)=-12b^2-16bc-15bc-20c^2 10)(2x-5y)(3x-2y)=-6x^2-4xy-15xy+10x^2 7. 6)(x^3)^7=x^10 7)(-y^15)^3=-y^45 8)(b^6)^2=b^8 9)(z^3)^n=zn^3 10)(y^k)^5=yk^5 8. 6)8ab : 4b=2a 7)15xy : (-3 x)=5y 8)8xyz : (-2 xz)=-4y 9)(-12mn) : 4mn=-3